Flash tube for ignition of gas burners



Aug, 8, 1950 F. A. GAUGER 2,517,782

FLASH TUBE FOR IGNITION OF GAS BURNERS Filed Feb. 5, 1944 INVENTOR.fP/r/v/r A 6/41/66? BY w my Patented Aug. g, 1950 2,517,782 FLASH TUBEFOR IGNITION OF GAS RN ERS Frank A. Qauger, Milwaukee, Wis. ApplicationFebruary 5, 1944, Serial No. 521,201

2 Claims. (Cl. 158-115) This invention relates to automatic lightingmeans for gas burners, particularly ior oven burners.

In gas stoves of the type generally known as the table top type the ovenburner is located below and laterally of the constantly burning pilotlight. In these constructions considerable difllculty has beenexperienced in causing an igniting flame to travel downwardly, orlaterally and downwardly from the constantly burning pilot light to theoven burner. There is a tendency for a cloud of water vapor to form inthe downwardly extending flashback tube and effectively block thesubsequent propagation of the flame after an initial operation. Inaddition to the above, great dimculty is occasioned due to the fact thatas the flashback tube heats up during operation of the oven, the stackvelocity in the downwardly extending flame conducting pipe increasesmaterially and frequently attains such a value that downward propagationof the flame is impossible. In addition to these defects, it has beenfound that there is considerable condensation resulting in dripping fromthe flashback tubes in the heretofore known devices.

This invention is designed to provide means for igniting an oven burnerwhich is located below and usually laterally Of a constantly burningpilot light, such ignition means being so arranged that thereis nointerference with ignition although the downwardly extending flashbacktube is heated during the operation of the burner, in which there is nopossibility of a cloudof water vapor forming in the flashback tube andpreventing downward propagation of the name, and in which there is nocondensation or dripping of moisture from the flashback tube.

Further objects are to provide a novel construction of a downwardlyextending flashback or flame conducting tube, which is so arranged thatalthough the tube becomes heated during the operation of the burner thestack velocity for the combustible mixture does not attain such speed asto prevent downward propagation of the flame. in which means areprovided for maintaining communication between the inside of the tubeand the outside air, such means extending longitudinally of the tube andbeing so designed as to maintain a continuous and unbroken column ofcombustible mixture within the tube from the lower to the upper endthereof prior to ignition, and being so arranged as to prevent a violentexplosive action when ignition takes place.

Embodiments of the invention are shown-in the accompanying drawings, inwhich:

Figure 1 is an elevation partly broken away and partly in section, ofthe ignition means.

Figure 2 is a side elevation, partly in section and partly broken away,looking at the left upper portion of Figure 1.

Figure 3 is a. sectional view on the line 33 of Figure 2.

Figure 4 is a sectional view on the line 4-4 01' Figure 1.

Figure 5 is a sectional Figure 1.

Figure 6 is a sectional Figure 1.

Figure 7 is a sectional view corresponding to Figure 6 showing amodified form of construction.

In describing this'invention it is to be understood that an ovenregulator, not shown, is so arranged that a manually opened valve, whichis not automatically controlled, turns on a supply of gas to the pipei3, see Figures 1 and 4, which pipe supplies a subburner and anextension burner hereinafter described. A part of the oven burner isindicated at 3 in Figure 1 and an extension of the oven Figures 1, 4,and 5. p

The pipe l3 leads to a sub-burner indicated generally by the referencecharacter It, see Figure 1, and supplies such sub-burner through anadjustable Bunsen mixer indicated at IS. The

view on the line 5-5 of view on the line 8-6 of sub-burner is located atthe bottom. of a downwardly extending flame conducting tube indicatedgenerally by the reference character It. This downwardly extending tubeterminates at its lower end in an upwardly converging conical hollowmember II which is adapted to collect the combustible mixture from thesub-burner l4 and to lead such mixture into the tube It. The upper endof the tube extends into a fitting l8 which has a laterally extendingoutlet portion l9, such portion being preferably slightly turneddownwardlypn its upper side as shown most clearly in Figure 3. Thefitting I8 is rigid with an extension burner 20 which is supplied with acombustible. mixture through the pipe 2| communicating with the interiorof the sub-burner M, as shown'in Figure 3. a The extension burner 20projects the combustible mixture into a laterally extending flameconducting pipe 22 which is seated within a portion of the fitting l8and also seated within the housing surrounding a constantly burningpilot light, not shown. a i

It is to be noted particularly from Figures 6 and 7 that the sub-burnerI4 is provided with a U-shaped extension 23 which is in lightingrelation with the oven burner 3 by means of the exburner is indicated at1 in tension 1 of the oven burner. It is to be noted also that anintermediate portion of the extension 23 of the sub-burner I4 is inlighting relation with the extension I of the oven burner and that theextreme end of extension 23 of the sub-burner is adapted to heat one endof a thermocouple 24. The reason for having the thermocouple at theextreme end of the extension 23 is to insure that the combustiblemixture is lighted throughout the entire extent of the extension 23 toinsure lighting of the oven burner. The thermocouple 24 is connected bymeans indicated at 25 in Figure 5 with control means, not shown.

The gas from the pipe l3 passes through the Bunsen mixer l5 and suppliesa combustible mixture to the sub-burner i4 and its extension 23 and alsosupplies combustible mixture to the extension burner 20. The sub-burnercharges the downwardly extending tube IS with a combustible mixture andthe extension burner 20 charges the laterally extending tube 22 with acombustible mixture. The combusttble mixture in the laterally extendingtube 22 is ignited from a constantly burning pilot light, not shown, andthe extension burner 20 is, therefore, lighted. It is to be noted thatthe slightly downwardly extending opening I! projects the combustiblemixture from the upper end of the downwardly extending pipe I6 intoproximity to the extension burner 20 and consequently such combustiblemixture is ignited and the flame travels down the tube It and lights thesub-burner H, the extension 23 also lighting. Subsequently gas inallowed to pass to the oven burner 3 by means not shown. The oven burneris in lighting relation to the extension 23 by means of its extension Iand consequently the oven burner is lighted from the sub-burner.

In order to carry the flame downwardly of the downwardly extending pipel8, such pipe is made in a peculiar manner. It is so made that acontinuous unbroken column of combustible mixture extends from its lowerto its upper end prior to ignition and also is maintained prior toignition independently of the temperature of the tube I8 andconsequently independently of the stack velocity. This is accomplishedin several different ways. a few of which have been shown. It is to benoted from an examination of Figures 1 and 6 that the tube It consistsof an outer tube 63 and an inner tube 64, the marginal edges of theouter tube 63 overlapping the marginal edges of the inner tube 64 andsuch tubes being turned in opposite directions and being arranged innested relation. Each of these tubes has a widely open section extendinglongitudinally thereof which open section is spanned by the other of thetubes. It is to be noted that the tube 63 has outwardly extending edgesthat overlap or overhang the tube 64 and that the tube 64 has inwardlyoverlapping or overhanging edges which extend inwardly of the tube 83.This provides restricted vent spaces 65 on opposite sides which when thestack velocity is rapid allows the entrance of outside air, but this airis so directed that it causes a combustible column of mixture to bemaintained within the composite tube It and does not cause intimatecomming-ling of the outside air with all portions of the combustiblemixture in the tube It. Instead it has been found that a continuouscolumn of combustible mixture extends from the bottom to the upper endof the downwardly extending tube II. It is to be noted that the stackvelocity even when the tube is hot is not such as to prevent thedownward propagation of the flame. A deflnite predetermined quantity ofcombustible mixture passes through the Venturi like or funnel likemember i1 into the tube I6. The suction immediately above this memberI'I produced by the heated tube II is broken, so to speak, as the sideslots begin immediately above the member l1. Also at all points alongthe tube IS the suction, and consequently the stack velocity, cannotincrease above the desired limit as outside air is immediately drawnthrough the longitudinally extending slots 65 and consequently greatsuction is not exerted on the continuous column of combustible mixturecarried within the composite tube l8 and consequently the stack velocitynever exceeds the right value to insure downward propagation of theflame.

Instead of following the construction shown in Figure 6 otherconstructions may be employed. For example, as shown in Figure 7, thetube It is formed of spiral shape and has overlapping marginal edges oneof which is directed outwardly and the other of which is directedinwardly of the tube. These marginal portions overlap a slightly greateramount than the overlap shown in Figure 6 and provide a. longitudinallyextending slot 88.

It is to be noted that with this type of tube the outside air that isdrawn in serves to spin the mixture within the tube l6 and inasmuch asthe combustible mixture is of less specific gravity than the incomingair, it will be maintained in a solid unbroken column centrally of thetube It and the heavier incoming air will rotate externally of thisunbroken column of combustible mixture.

While preferred constructions of the downwardly extending tube have beenshown, it is to be distinctly understood that modifications could bemade without departing from the spirit of this invention. For exampleinstead of using the sheet metal type of tubes described, the tubescould be formed of cast metal provided the tubes had the characteristicshereinabove set forth. It is also apparent that the slot or slotsextending longitudinally of the tube need not be continuous. They couldbe formed by a series of openings provided the characteristicshereinabove set forth were maintained. From actual observation of thisapparatus while it is in operation, it has been found that there is atrailing flame on the outer side of the tube It as well as thepropagation of the flame downwardly interiorly of the tube l6. Thistrailing flame externally of the tube is most pronounced when the deviceis cold and is operated for the first time. As the device heats up, theoutside trailing flame becomes less and less prominent.

Another advantage which results from this construction is that theexplosion within the downwardly extending tube is softened up, so tospeak, and is not a violent cannon like blast. Instead it has only avery small explosive efiect making at most a very slight sound.

It will be seen that means have been provided by this invention forlighting a burner which is spaced downwardly and perhaps laterally of aconstantly burning pilot light, and that this means is so constructedthat prior to ignition it provides a continuous column of a combustiblemixture from the lower to the upper end of the downwardly extending tubeand maintains this column of combustible mixture in unbroken continuityirrespective of stack velocity or temperature of the downwardlyextending tube and also prevents excessive stack velocity which wouldpreclude the possibility of downward propagation of the flame.

It is to be noted also that the free venting of the tube insures thedischarge of any cloud of water vapor that might act as a plug toprevent subsequent ignition. Also it is to be noted that condensation isprevented within either the downwardly extending tube I6 or thelaterally extending tube 22. The downwardly extending tube is heated atits lower end from the subburner l4 and at its upper end from theextension burner 20 and is maintained at a temperature above that atwhich the condensation would occur at all points along its length. Alsothe tube 22 is heated at one endfrom the extension burner 20 and at itsother end from a constantly burning pilot light. Consequently nocondensation can occur at any point along its length as all portions ofthis tube are maintained at a temperature above that at whichcondensation would occur.

It will be seen further that this invention provides a constructionwhich is eminently practical and is easy to construct and is notdependent upon delicate and easily damaged parts and is foolproof.

Although this invention has been described in considerable detail, it isto be understood that such description is intended as illustrativerather than limiting, as the invention may be variously embodied and isto be interpreted as claimed.

I claim:

1. Ignition apparatus for causing the downward propagation of anigniting flame comprising a downwardly extending tube having an upperand a lower opening, a burner adjacent the lower opening for feeding acombustible mixture into said tube, said tube having a longitudinallyextending slot formed by overlapping radially spaced walls, and meansadjacent the upper end of said tube for igniting the column ofcombustible mixture to thereby cause downward propagation of the flameand lighting of said burner.

2. Ignition apparatus for causing the downward propagation of anigniting flame comprising a downwardly extending tube having an upperand a lower opening, a burner adjacent the lower opening for feeding acombustible mixture into said tube, said tube being formed of sheetmaterial having longitudinally extending, spaced, marginal portions withthe edge of one marginal portion spaced inwardly of the other along theradius of the tube to provide a longitudinal slot with overlappingspaced walls arranged to provide an arcuate longitudinally extendingpassage for the admission of outside .air between said walls, and meansadjacent the upper end of said tube for igniting the column ofcombustible mix ture to thereby cause downwardpropagation of the flameand lighting of said burner.

FRANK A. GAUGER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 413,809 Marsh Oct. 29, 18391,747,015 Leins Feb. 11, 1930 1,991,609 Furlong Feb. 19, 1935 2,048,065Gauger July 21, 1936 ,072,552 Gauger Mar. 2, 1937 2,087,433 Hollman July20, 1937 2,268,959 Ray Jan. 6, 1942 2,273,127 McGoldrich Feb. 17, 19422,303,672 Wantz Dec. 1, 1942 2,315,773 Couzens Apr. 6, 1943 2,334,603Brumbaugh et a1. Nov. 16, 1943 2,351,277 Mantz June 13, 1944 2,353,042Koch July 4, 1944 FOREIGN PATENTS Number Country Date 701,131 FranceAug. 4, 1930 827,388 France Oct. 1, 1937

